Dual Gpu in Mac Pro 5,1

[bsbeamer]

XFX cards tend to have issues with macOS. Some get them to work fine, while others run into major roadblocks.

FWIW, Sonnet does NOT certify any XFX GPUs for macOS usage via eGPU, see page 7:

https://www.sonnettech.com/support/downloads/manuals/Compatibility_Graphics_Cards.pdf

 

[ericjlein]

Hi guys, i registered an account just to let you guys know about my setup. I put 2 Radeon VII in my Mac Pro 12 core 2010 Mojave and it works like a charm! i did a lixlas mod then split it in to 4 8pins connectors. The Mac Pro PSU is 980w so it has enough power for 2 Radeon to run. the only thing is the fan is covered by the other card so i might want to put them in waterblock.
good luck to you whom want to do the same setup.

Funny, I just registered an account so I can ask you about the power setup.

 

[Kriss Parker]

I don’t have the magic of two Radeon VII but the configuration setup I have suites me Also have the “bootscreen” option!

Just one question... I have a 580 but no boot screen... in case I had to buy another 580, already with the flashed rom to get the boot screen and I choose to put it together with the one I have , once they are connected together, will I see a startup screen? tnx

 

[tommy chen]

install opencore and you will get a bootscreen with bootpicker
it works without flashing the card

if you use this new 0.5.8 version from martin, you will also
get HWacc for your RX580

Activate AMD hardware acceleration

I created a new "easy to install package" as per many requested (based on the official OpenCore). [The attached package updated to 1.0.0] For those who only need HWAccel, post #594 has everything you need. This new package mainly offer HWAccel + boot screen. Also, this package should work in...

forums.macrumors.com

 

[Kriss Parker]

install opencore and you will get a bootscreen with bootpicker
it works without flashing the card

if you use this new 0.5.8 version from martin, you will also
get HWacc for your RX580

Activate AMD hardware acceleration

I created a new "easy to install package" as per many requested (based on the official OpenCore). [The attached package updated to 1.0.0] For those who only need HWAccel, post #594 has everything you need. This new package mainly offer HWAccel + boot screen. Also, this package should work in...

forums.macrumors.com

tnx so much...

 

[zedex]

That lower card won't like running like that long term!

Configure it the same as I have done mine, there is zero difference using a 4x slot over a 16x slot for most apps, try it and see for yourself.

If you use a pair of long nosed pliers, you can easily bend the little metal tab at the top of slot 4 out of the way.


View attachment 890346

Hi @IanK MacPro -- it's very encouraging to see another cMP 5,1 build that embraces the use of Slot 4 for GPU installations. I have attached a couple of images depicting my approach to Slot 4 installation with a professionally machined GPU bracket to ensure both the appearance AND the function of the GPU was not compromised in any way. See my pictures.

Having said that I'm interested in your approach because it seems slightly different but equally clean and functional. Can you take a picture from the rear so I can see if your installation looks "flush"? I've got a number of new GPUs and I dont want to go back to the industrial metal cutting workshop if your approach/solution is as neat as it looks!!

Thanks in advance

PS - your PIXLAS mod cabling effort/arrangement is easily amongst the best I've seen. Was this careful assembly of multiple component parts OR were you able to purchase the materials in a [pre-packaged] kit..? if so - where (please)..?

--

-- 15mm clearance

-- One method of preserving full access to backplane SATA II ports

 

[Noobraino]

Hey guys!

Amazing how many helpful content there is on this site!

I recently bought a flashed(boot screen) Sapphire Pulse Radeon RX580 8gig for my cMP 5.1

I’m thinking about riging another one in it using the Pixlas Mod.

Is the second card needs to be flashed also if i want the boot screen to be working or it can be a unflashed card? Obviously it is a lot cheaper unflashed that’s why i’m asking.

Thanks in advance.

 

[tsialex]

Hey guys!

Amazing how many helpful content there is on this site!

I recently bought a flashed(boot screen) Sapphire Pulse Radeon RX580 8gig for my cMP 5.1

I’m thinking about riging another one in it using the Pixlas Mod.

Is the second card needs to be flashed also if i want the boot screen to be working or it can be a unflashed card? Obviously it is a lot cheaper unflashed that’s why i’m asking.

Thanks in advance.

No need to flash the second card, but needs to be identical, you can't use a RX580 + a VEGA GPU for example.

Dual GPU after Mojave need to be made with pairs of cards.

 

[Noobraino]

@tsialex thanks again my man!

Does the flashed card needs to stay in pci-e slot 1?

 

[Noobraino]

What’s up guys,

Yesterday i did the pixlas mod and wanted to install a second RX580 in my cMP. I wanted to have one GPU in slot 1 and one in slot 4 but unfortunately for slot 4 the DVI port on the GPU block the access of the PCI-e slot.

Is it feasible to remove this DVI port? If so is it complicated? A no go? What things i need to be careful about?

Thanks.

 

[Noobraino]

@tsialex i know that you post that i need to have the exact same GPU model (which i did) but i see that Sapphire sells a RX580 model without the DVI port, they call it “lite”. Other then that the GPU seems to be exactly the same.
I was thinking that i could sell the second one i bought with the DVI port and buy that “lite” version. That way i will be able to make it fit into the slot 4 without the needs to modify the backplate of the cMP which i don’t really wanna do.

What do you think? Should this model work (no dvi) with the DVI model?

Thanks.

 

[MarkC426]

Surely it should take two of the rear slots just like your original card?
Do you have a photo at the back of your Mac.

 

[Noobraino]

Yes the card without the DVI port will take 2 slots also. But it seems that it would fit in slot 4 if it dont a slight modification cpuld make it fit but if i keep the card with the DVI port and want it to fit slot 4 a bigger modif is needed which probably incolve cuting the case. I don’t wanna do this.

 

[MarkC426]

No I mean the one with the dvi....why will it not fit?

 

[Noobraino]

Because it is a 2 slots cards, so the DP and HDMI ports fits into the last available access lane in the back of the MacPro (slots 4) but the DVI port is over these connections so it bump into the frame of the cMP (internaly) so i’m obviously not able to make it connect into the PCI-E lane.

If i had the no DVI card i could modify the bracket to something like this and make it fit perfectly in slot 4

 

[MarkC426]

Plug it into slot 3.

 

[KeesMacPro]

Unfortunately there are several reports that the RX 580 Sapphire lite version (without dvi) causes issues/doesnt work in the MP.

 

[Noobraino]

@KeesMacPro

Thanks a lot for this! I was about to buy one.

 

[Noobraino]

@MarkC426

I guess you didn't read or saw the pictures I posted earlier ;p

Both are installed in slot 1 and 3 right now but it cost me a slot, that's why I want to put it in slot 4 and 1.

 

[bsbeamer]

Look at PCIe extension ribbon cables, might be able to salvage a slot if you don’t mind a franken setup.

 

[tsialex]

I'm honestly falling to see any benefit of having all this trouble. Why you don't sell both cards and get a VII?

VII is the compute king card with macOS, you will get a lot better compute throughput from one VII than two RX580.

 

[Noobraino]

Tsialex 1
Me 0

 

[tsialex]

Tsialex 1
Me 0

The only scenario that dual cards are necessary is when you have 6+ displays. For everyone that is not using a display wall, a VII will always be a better choice.

 

[Noobraino]

Alright, Radeon VII don’t go for less then ~1200$ CAD so i will probably go an other way. I already own a Sapphire Pulse RX5700 XT and i’m happy so far with it, content creation wise should i sell my 2 Sapphire Radeon RX580 and go for the same RX5700 XT or a Vega Frontier will be better? I know the later one is already 3 years old but they seems to go very cheap nowadays.

 

[tsialex]

Alright, Radeon VII don’t go for less then ~1200$ CAD so i will probably go an other way. I already own a Sapphire Pulse RX5700 XT and i’m happy so far with it, content creation wise should i sell my 2 Sapphire Radeon RX580 and go for the same RX5700 XT or a Vega Frontier will be better? I know the later one is already 3 years old but they seems to go very cheap nowadays.

Depends on what you want to do and when.

Today, for compute jobs, the VEGA Frontier will be faster than RX5700XT, but the VCN 2.0 of NAVI cards is a improvement over VCE/UVD of VEGA cards and in the future, video compression/decompresson via VideoToolbox API will be better with RX5700XT.

Vega Frontier has another advantage, older macOS releases like 10.13.6 are supported while NAVI cards require Catalina.